Given a projectile at position '(x0, y0)' and a launch angle 'a', at which speed must I launch the projectile to make it pass through a point '(x, y)', assuming that the only force that acts upon it is gravity (which causes acceleration 'g')?(adsbygoogle = window.adsbygoogle || []).push({});

I came up with the following:

vx0 = s * cos(a)

vy0 = s * sin(a)

x = x0 + vx0 * t

y = y0 + vy0 * t + g/2 * t^2

x = x0 + s * cos(a) * t

y = y0 + s * sin(a) * t + g/2 * t^2

s = -((x0 - x) * sec(a)) / t

y = y0 -((x0 - x) * sec(a)) / t * sin(a) * t + g/2 * t^2

y = y0 - (x0 - x) * tan(a) + g/2 * t^2

t = +- (sqrt(2) * sqrt(y - y0 - x * tan(a) + x0 * tan(a)) / sqrt(g)

But there's no point in going any further because of 'sqrt(g)', which is a square root of a negative value.

I tried doing it the other way around, but that also yields a complex solution.

Can anyone help me out with this?

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# Homework Help: Projectile Launching

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